Method and apparatus for selecting radio access network device

Abstract

This application relates to the field of wireless communications technologies, and provides a method for selecting a radio access network device. The method includes: obtaining, by a first RAN device, capability information of a second RAN device, where the capability information is used to indicate an LADN supported by the second RAN device; and sending, by the first RAN device, a handover request message to the second RAN device.

What is claimed is: 
     
       1. A method, comprising:
 obtaining, by a first radio access network (RAN) device, capability information of a second RAN device, wherein the capability information indicates a local area data network (LADN) supported by the second RAN device, and the capability information comprises a data network name (DNN) of the LADN, an internet protocol (IP) address or prefix of the LADN, or IP routing information of the LADN; 
 in response to determining, according to the capability information of the second RAN device, that the second RAN device supports the LADN, selecting the second RAN device to handover a terminal device; and 
 sending, by the first RAN device, a handover request message to the second RAN device. 
 
     
     
       2. The method according to  claim 1 , wherein obtaining, by the first radio access network RAN device, the capability information of the second RAN device comprises:
 sending, by the first RAN device, a connection setup request message to the second RAN device; and 
 receiving a connection setup response message from the second RAN device, wherein the connection setup response message comprises the capability information of the second RAN device. 
 
     
     
       3. The method according to  claim 1 , wherein before sending, by the first RAN device, the handover request message to the second RAN device, the method further comprises:
 determining, by the first RAN device, that the terminal device is currently accessing the LADN using a first session. 
 
     
     
       4. The method according to  claim 3 , further comprising:
 receiving, by the first RAN device, an association between a session identifier of the first session and a first network name of the LADN from a session management function (SMF) network element. 
 
     
     
       5. The method according to  claim 3 , further comprising:
 receiving, by the first RAN device, a second network name from a session management function (SMF) network element, and determining that the second network name corresponds to the LADN. 
 
     
     
       6. The method according to  claim 1 , wherein the capability information comprises:
 a correspondence between a cell identifier or a tracking area identifier and the DNN of the LADN, the IP address or prefix of the LADN, or the IP routing information of the LADN of the LADN. 
 
     
     
       7. A method, comprising:
 obtaining, by a second radio access network (RAN) device, capability information of the second RAN device from an access and mobility management function (AMF) network element, wherein the capability information indicates a local area data network (LADN) supported by the second RAN device, and the capability information comprises a data network name (DNN) of the LADN, an internet protocol (IP) address or prefix of the LADN, or IP routing information of the LADN; 
 sending, by the second RAN device, the capability information to a first RAN device; and 
 receiving, by the second RAN device, a handover request from the first RAN device requesting to handover a terminal device to the second RAN device, the second RAN device being selected for the terminal device to handover to according to the second RAN supporting the LADN. 
 
     
     
       8. The method according to  claim 7 , wherein obtaining, by the second RAN device, the capability information of the second RAN device from the AMF network element comprises:
 obtaining, by the second RAN device, the capability information of the second RAN device from the AMF network element in a process of setting up a connection between the second RAN and the AMF network element. 
 
     
     
       9. The method according to  claim 7 , wherein sending, by the second RAN device, the capability information to the first RAN device comprises:
 receiving, by the second RAN device, a connection setup request message from the first RAN device; and 
 sending a connection setup response message to the first RAN device, wherein the connection setup response message comprises the capability information. 
 
     
     
       10. The method according to  claim 7 , wherein the capability information comprises:
 a correspondence between a cell identifier or a tracking area identifier and the DNN of the LADN, the IP address or prefix of the LADN, or the IP routing information of the LADN. 
 
     
     
       11. An apparatus, configured to act as a first radio access network (RAN) device, the apparatus comprising:
 a processor; and 
 a non-transitory computer-readable storage medium storing a program to be executed by the processor, the program including instructions for:
 obtaining capability information of a second RAN device, wherein the capability information indicates a local area data network (LADN) supported by the second RAN device, and the capability information comprises a data network name (DNN) of the LADN, an internet protocol (IP) address or prefix of the LADN, or IP routing information of the LADN; and 
 in response to determining, according to the capability information of the second RAN device, that the second RAN device supports the LADN, selecting the second RAN device to handover a terminal device; and 
 
 sending a handover request message to the second RAN device. 
 
     
     
       12. The apparatus according to  claim 11 , wherein the instructions for obtaining the capability information of the second RAN device comprise instructions for:
 sending a connection setup request message to the second RAN device; and 
 receiving a connection setup response message from the second RAN device, wherein the connection setup response message comprises the capability information of the second RAN device. 
 
     
     
       13. The apparatus according to  claim 11 , wherein the program further includes instructions for:
 before sending the handover request message to the second RAN device, determining that the terminal device is currently accessing the LADN using a first session. 
 
     
     
       14. The apparatus according to  claim 13 , wherein the program further includes instructions for:
 receiving an association between a session identifier of the first session and a first network name of the LADN from a session management function (SMF) network element. 
 
     
     
       15. The apparatus according to  claim 13 , wherein the program further includes instructions for:
 receiving a second network name from a session management function (SMF) network element, and determining that the second network name corresponds to the LADN.